Power-operated, gear-controlled torque wrench



1952 J. c. CURTIS EI'AL 2,606,472

POWER-OPERATED GEAR-CONTROLLED TORQUE WRENCH Filed June 15, 1950 [igl-Ez'y. 6;.

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Patented Aug. 12, 1952 POVVERl-OPERATED, GEAR-CONTROLLED TORQUE WRENCHJohn 0. Curtis and George E. Thompson, Claremont, N. H., assignors toJoy Manufacturing Company, Pittsburgh, Pa., a corporation ofPennsylvania Application June 15, 1950, Serial No. 168,266

v 14 Claims. 1

This invention relates to power wrenches and more particularly to atorque wrench especially, but not exclusively, designed for use with astoper drill for tightening the nuts of. roof anchor bolts forsupporting the roof strata of an underground mine or tunnel, V V

In underground mines or tunnels it is becoming the common practice tosupport the roof against roof-falls and cave-ins by means of suspensiontype roof anchor bolts which are inserted in holes drilled in the roofstrata to bind together the stratathereby to minimize flexure and thusprevent failure of the roofrock. .The holes are frequently drilled inthe roof strata by meansof pneumatic hammer drills commonly known asstopers, and when the holes are drilled at proper locations anchorbolts; of the expanding head type are inserted in the holes and theheads thereof are expanded to secure the anchor bolts firmly inpositions. Roof plates are then placed over the projecting lower ends ofthe bolts, against the roof, and nuts threaded on the bolt ends aretightened, usually by separate power wrenches, to secure the roofsupporting plates in proper position. The present invention contemplatesimprovements over known types of power wrenches in that a wrench isprovided which is substituted for the usual drill steel of the stoperdrill so that the drill is employed to position, support and drive thewrench. The wrench of the present invention embodies a shank receivablein the rotatable chuck of the stoper drill and this shank drives throughgearing a rotatable wrench member which engages the nut of the anchorbolt, and pointed abut- 'ment; rods are carried by the bottom supportofthe wrench and are held up against. the roof by the usual pneumatic feedleg of the stoper thereby to hold the wrench steady and to absorb torquereaction which is present during opera tion of the wrench. The rotatablewrench member is yieldingly suppgrted by springs engaging the bottomsupport and surrounding the abutment rods so that in the event therotatable wrench member does not properly engage the nut of the anchorbolt, it may yield or spring back without damage to the parts. Thegearing for driving the rotatable wrench member is driven by therotating mechanism of the stoper drill, and the gearing provides asubstantial speed reduction between the rotating drill chuck and thewrench member thereby to obtain a relatively powerful rotating torquesufficient properly to tighten the nuts of the anchor bolts. I

An object of the present invention is to pro: vide an improved powerwrench. Another object is to provide an improved torque wrench fortightening the nuts of bolts, and having novel driving means for therotatable wrench member which engages the nuts. A further object is toprovide an improved power wrench which may be firmly supported againstthe work and which has-an improved yieldable mounting for the rotatablewrench member whereby the latter may yield or spring'back in the eventthe nut to be tightened is improperly engaged thereby. A still furtherobject is to provide an improved torque wrench havingabutment engagingmeans whereby the wrench may be firmly held against an extraneousabutment during operation of the wrench and whereby the torque reactionset up during the nut tightening operation is-substantially absorbed.Yet another object is to provide an improved torque wrench especiallydesigned for use with a pneumatic hammer drill whereby the drillrotating mechanism may be employed to operate the wrench. A stillfurther object is to provide an improved torque wrench having novelplanetary driving gearing and improved mounting means. These and otherobjects and advantages of the invention will, however, hereinafter morefully appear in the course of the ensuing description.

In the accompanying drawing there is shown for purposes of illustrationone form which the invention may assume in practice:

In this drawing:

Fig. 1 is an elevational view of a pneumatic hammer drill-of the stopertype with which the improved torque wrench is associated, showing thewrench in operative engagement with the nut of a roof anchor bolt.

Fig. 2 is an enlarged vertical sectional view taken through the improvedwrench and through the front chuck of the associated stope'r drill.

Fig. 3 is an enlarged cross section taken on line 3-3 of Fig. 2,illustrating the planetary drivin gearing.

In this illustrative embodiment of the invention, as shown in thedrawing, the improved torque wrench, generally designated I, is shownassociated with a conventional pneumatic hammer drill of the stopertype, generally designated 2. Evidently, the improved torque wrench maybe associated with tools of other types.

The stoper drill 2 is of the type known as a roof bolt hole drill fordrilling upright holes in the roof strata of an underground mine ortunnel, and generally comprises a pneumatic hammer motor 3 which issupported and fed toward the work by a pneumatic feed leg 4' which isdisposed along one side of the hammer motor in parallelism with thelatter to provide for longitudinal compactness. A drill embodyinggenerally similar features is disclosed in the copending application toJ. C. Curtis, Ser. No. 139,612, filed January 20, 1950, and owned byapplicants assignee. The hammer motor 3 includes a motor cylinder 5which contains a reciprocable fluid actuated hammer piston (not shown)having a front striking bar 6 (Fig. 2) which is adapted to actuatepercussively a conventional drill steel. The hammer piston, in the drillof this type, rotates intermittently as it reciprocates and the pistonrotation is transmitted through a chuck nut I to a chuck 8 rotatablymounted in a front chuck housing 9 of the drill. Secured within therotatable chuck is a chuck bushing IIl having a polygonal socket II forreceiving the polygonal shank of the drill steel (not shown) which isemployed to drill the holes in the roof strata. The feed leg 4 forfeeding the drill steel toward the work during the drilling operationand for holding the wrench up against the room during tightening of theroof anchor bolts comprises a reciprocable feed cylinder I2 containing afeed piston (not shown) having its piston rod I3 extending downwardlyfrom the cylinder and engaging the mine or tunnel floor. The drill has alateral handle I4 provided with a grasping portion I4 whereby the drillmay be positioned and supported with respect to the work, and may beheld against rotation about its longitudinal axis during its operation,all in a manner well known to those skilled in the art.

When drilling is completed and it is desired to tighten the roof anchorbolts inserted in the drill holes, the drill steel is removed from thedrill chuck and a polygonal shank I5 of the torque wrench i is insertedin the socket I i of the chuck bushing. 19 of the drill chuck, as shownin Fig. 2.

This polygonal shank I5 has a collar I5 and is ro tatably secured at Itto a transverse bottom support I! with the latter engaging the collar,and an upper polygonal portion I8 of the shank extends upwardly within apolygonal opening or socket I9 in a rotatable member 20, as laterexplained more in detail. Thus, an axial self-adjusting or extensible,sliding connection is provided between the parts I8 and 20. The bottomsupport member I? has lateral lugs 2| formed with longitudinal bores 22for receiving the lower portions of parallel abutment engaging rods 23,the latter having upper pointed ends 24-. These rods are detachablysecured down within the bores of the bosses 2I by screws 25 threaded at26 within the lower portions of the rods and having cooperating washersengaging the bottom surface of the bottom support I'I. Slidably engagingthe parallel rods 23 are lateral perforated lugs 2'! formed integralwith a non-rotatable frame or gear housing 28 and encircling the rods 23and arranged between the bosses 2I and the lugs 2! are resilientelements desirably in the form of coil springs 29 for constantly urgingthe housing 28 upwardly along the rods toward a position wherein thelugs 2'! abuttingly engage stop collars 30 secured to the rods.Themember 20 is rotatably mounted in a bearing sleeve 32 supportedwithin the lower portion of the housing 28 and keyed at 33 to the upperportion of the member 20 is a spur gear 34; This gear at its oppositesides meshes with planet gears 35 journaled on bearing sleeves 36supported by parallel stub shafts 37' in turn rigidly mounted in arotatable carrier 38. The lower portion of this carrier is journaled ona bearing sleeve 39 supported by the member ill,

as shown in Fig. 2. The planet gears 35 mesh with the teeth of aninternal gear 40 secured to the non-rotatable housing 28. Formedintegral with the upper portion of the rotatable carrier 38 is a shaftelement 42 journaled in a bearing sleeve 43 supported by a top cover 45detachably secured, as by bolts, to the top of the gear housing 28. Therotatable member 20 has a reduced upward projection 55 journaled in abearing sleeve 45 supported by the rotatable carrier thereby to providean upper bearing support for the member 20.

In this improved construction a transverse I frame ll has lateral bosses48 formed with bores 49 through which the upper portions of the abutmentrods 23 extend, and these bosses are secured as by screws 50 orotherwise to the abutment rods whereby the transverse frame rigidlybraces the upper portions of the abutment rods. A collar 5I isthreadedly secured to the shaft element 52 and secured, as by welding,or otherwise, to this collar is a rotatable wrench member 52 formed witha polygonal socket 53 for receiving a nut 54 of the roof anchor bolts 55(see Fig. 1).

When the torque wrench has its polygonal shank I 5 inserted in the chuckof the stoper drill, as shown in Fig. 2, in place of the usual steelshank, the pneumatic feed leg 2 may be operated in a known manner tomove the Wrench upwardly toward the roof of the mine or tunnel to bringthe points 24 of the abutment rods 23 into firm engagement with the roofas shown in Fig. 1, and the feed leg holds the wrench up against theroof during tightening of the nut of the anchor bolt. As the hammermotor 3 of the stoper is operated to rotate the chuck 8, the shank I5and the polygonal portion I8 are rotated therewith relative to thebottom support ll of the wrench and as a result the spur gear 34 isrotated. This spurgear drivingly engages the planetgears 35 causing thelatter to revolve about the stationary internal gear 40 as a trackwayrotating the carrier 35 therewith at a speed substantially slower thanthe speed or rotation of the drill chuck. Thus, the shaft element 42 isdriven at a reduced speed but with a relatively powerful torque,rotating therewith the wrench member 52. This wrench member engages thenut 54 of the anchor bolt 55. As the torque wrench is fed upwardlytoward the work by the pneumatic feed leg 2 of the stoper to bring thepoints 24 of the abutment rods 23 against the roof and the rotatablewrench member 52 does not properly engage the nut 54 the wrench membermay yield or spring back due to the spring mounting for thegear housing28. As the springs 29 yield, the perforated lugs 2! of the gear housingmay slide downwardly along the abutment rods 23 and at that time themember 20 may slide axially rearwardly relative to the polygonal portionI8 of the rotatable shank. Any percussion action of the hammer piston isabsorbed by this axial sliding connection between the parts I8 and 20,sotlitst no hammer blows are transmitted to the gear housing. Ifdesired, the shank I5 may be slightly shorter than the conventionaldrill steel shank, so that the piston striking bar 6 will at no timestrike against the shankI5.' I

As a result of this invention an improved power wrench is provided whichis especially designed for tightening the nuts of bolts. By theprovision of the planetary speed reducing gearing. the wrench may beoperated by the rotating mechanism of a conventional stoper drillthereby to impart a-powerful rotating torque to the nut to be tightened.By yiel'dingly mounting the gearing housing :and socket "wrench memberon the bottom support of the wrench the socket wrench memberimay yieldor spring back in the event it improperly engages the nut tobetightened. The abutment engaging rods secured to the bottom supportofthe" wrench firmly engage the roof of the mine or tunnel or otherextraneous abutment to-hold the wrench steady during its operation andtoabsorb the torque action set up by the wrench during its operation. Thewrench is simple and rugged in design and is readily adapted to use witha conventional hammer drill of the stoper type without change. Otheradvantages of the invention will be clearly apparent to those skilled inthe art.

While there is in this application specifically described-one form whichthe inventionmay'assurne in practice, it'will be understood that thisform of the same is shown for purposes of illustration and thattheinvention may besmodified and embodied-in various other forms withoutdeparting from its spirit or the scope of the appended claims. I What weclaim as new and'desire to secure by Letters Patent is:

*1. A torque wrench comprising, in combination, a support, aself-contained speed reducing andwrench unit comprising reductiongearing and a wrench member driven by said gearing, means for yieldinglymounting said self contained unit on said support for movementlongitudinally relative thereto whereby said unit may yield rearwardly,a rotatable driving member journaled' on said support and adapted fordetachable connection with a power source, and l an extensible drivingconnection between said gearing and said rotatable driving member.

2. A torque wrench comprising, in combination, a bottom support,parallel guide members secured to the opposite sides of said support andextending longitudinally in advance of said support, a housing extendingbetween and slidable along said guides, resilient elements encirclingsaid guides-for yieldingly urging said housing in' a forward direction,a driver rotatably mounted on said support, driving gearing contained insaid housing, a self-adjusting driving connection between said driverand said driving gearing for driving the latter in all positions of saidhousing along said guide members, and a wrench member ro'tatably mountedon said housing and driven by said gearing.

3. A torque wrench comprising, in combination, a bottom support, arotatable driver journaled on said support, parallel abutment rodssecured tosaid bottom supportat its opposite sides and extendingforwardly in advance of said support into engagement with an extraneousabutment, ahousing extending between, and slidably guided onsaidparallel rods, springs encircling said rods for urging said housing in aforward direction, gearing contained-in said housing, an extensibledriving connection between said driver and said gearing, and a rotatablewrench member journaled on said housing and driven through said gearing.

4. A torque wrench comprising, in combination, a bottom support, arotatable driver journaled on said support and adapted for connection toa power source, parallel abutment rods secured to said bottom support atits opposite sides and extending forwardly in advance of said supportinto engagement with an extraneous abutment, a housing extending betweenand slidably guided on said parallel rods, a cross frame extendingbetween and secured to the forward portions of said parallel rods inadvance of said housing for laterally bracing said rods, springsencircling said rods for urging said housing in a forward directionalongsaid rods, gearing contained in said housing, an extensible drivingconnection between said driver and said gearing, and a rotatable wrenchmember journaled on said housing and driven through said gearing.-

5. A torque wrench comprising, in com-bina tion, a bottom support, arotatable driver-journaled on said support and adapted for connection toa power source, parallelabutment rods secured to said bottom support atits opposite sides and extending forwardly in advance of said supportinto engagement with an extraneous abutment, a housing extending betweenand slidably guided on said parallel rods, springs encircling said rodsfor urging said housing in a forward direction, gearing containedin saidhousing, means providing a sliding connection between said driver and anelement of said gearing whereby said' driver may drive said gearing inall positions of, said housing along said parallel rods; and a rotatablewrench member journaled on said housing and driven through said gearing;

'6; A torqu wrench comprising, in combination, supporting meansincluding a bottom support, a driver journaled on said support centrallyof the wrench and adapted for connection to a source of power, anon-rotatable housing, means for yieldingly mounting said housing onsaid supporting means for movement longitudinally relative thereto, agear journaled within said housing, a self-adjusting sliding connectionbetween said driver and said gear, planet gears within said housing andmeshing with and driven by said gear, a rotatable carrier for saidplanet gears mounted for rotation within said housing, an internal gearsecured to said non-rotatable housing and with whichsaid planet gearsmesh, and a rotatable wrench member journaled on said housing andsecured-to said carrier and driven by the latter through said planetarygearing.

'7. A torque wrench comprising, in combina-. tion, a bottom support,longitudinal guiding means carried by said bottom support, a rotatablewrench member mounted for guided. movement longitudinally along saidguiding means, yieldable means for urging said Wrench member in aforward direction along said guiding means, and driving means for saidwrench member including a driver journaled on said bottom support andadapted for connection with a source of power and an extensibleself-adjusting driving connection between said driver and said wrenchmember.

' 8. In a torque wrench, the combination comprising a bottom support,longitudinal guiding means carried by said bottom support, a frameguided on said guiding means'for longitudinal movement relative to saidbottom support, driving means carried by said frame, a driver journaledon said bottom support, and an extensible driving connection betweensaid driver and an element of said reduction gearing, an extensibledriving connection between an element of said driving means and saiddriver, resilient means acting between said bottom support and saidframe for urging said frame forwardly along said guiding means, and arotatable wrench member journaled on said frame and driven through saiddriving means, said resilient means permitting said frame and wrenchmember to yield rearwardly along said guiding means in the event said 9.In a torque Wrench, the combination comprising a bottom support,longitudinal guiding means carried by saidbottom support and engageablewithan extraneous abutment for holding said bottom support againstrotation, a housing guided on said guiding means for longitudinal.movement relative to said bottom support, reduction gearingcontained insaidhousing, a rotatable driver .journaled on said bottom support,.a.sliding driving connection between a gear of said gearing and saiddriver, springs for urging said housing forwardly along said guidingmeans, and a rotatable wrench member journaled on saidhousing and driventhrough said gearing, said springs permitting said housing to yieldrearwardly along said guiding means in the event said wrench memberimproperly engages an element to be tightened. "10. In combination, apower actuator having arotatablechuck'and an extensible power operated?feed. leg, and a, torque wrench having a bottom support, a rotatabledriver engageable with said chuck and'rotatable thereby, abutmentengaging'elements secured to said support and adapted to be held' bysaid feed leg in engagement with an extraneous abutment, a'housing onsaid support, speed reducing gearing contained in said housing anddriven by said chuck through said driver, and a rotatable wrench memberjournaled on said housing and driven through said gearing, said wrenchmember being adapted to engage an element to be rotated.

11. In combination, a power. actuator having a rotatable chuckandian'extensible power operated feed leg, and a torque wrench adaptedfor detachableconnection with the actuator and comprising a bottomsupport, a driver journaled on said support and having a shank,receivable in said chuck whereby said chuck may effect rotation of saiddriver, parallel abutment rods secured. to the sides of said bottomsupport and extending'forwardly in advanceof'said support, said rodsbeing adapted to be moved toward and tolbe held in engagement with anextraneous abutment by said extensible feed leg of the actuator, arotatable wrench member adapted for engagement with an element to betightened, and means on said support and driven by said driver forrotating said wrench member. I

12'. In combination, a power actuator having arotatable chuck and anextensible power operated feed leg, and a torque wrench adapted fordetachable connection with the drill and comprising a bottom support, adriver journaled on said support and having a shank receivable in saidchuck whereby said chuck may effect rotation of said driver,- parallelabutment rods secured to the sides of said bottom support and extendingforwardly in advance of said support, said rods being adapted to bemoved toward and to be held in engagement with an'extraneous abutment bysaidextensible fe'ed'leg of the actuator, a housing slidably engagingsaid parallel rods, springs encircling said rods for urging said housingin a forward direction with respect to said bottom support, reductiongearing contained in said housing, a sliding connection between anelement of said gearing and said driver whereby said driver may drivesaid gearing in all positions of said housing along said abutment rodsrelative to the actuator, and a rotatable wrench member journaled onsaid housing and driven through said gearing, said wrench member beingadapted to engage an element to be tightened.

13. In combination, a power actuator having a rotatable chuck, and atorque wrench unit adapted for detachable connection with said poweractuator and having a rotatable shank receivable in said chuck androtatable thereby, speed reducing gearing driven by said shank, arotatable wrench member driven throughsaid reduction gearing, ayieldable mounting for said wrench member on said actuator whereby saidwrench member may yield rearwardly relative thereto in the event ofimproper engagement thereof with an element to be rotated, and aselfadjusting driving connection between said rotatable shank and saidspeed reducing gearing whereby the drive between the actuator chuck andsaid wrench member is maintained in all the yielded positions of saidwrench member relative to said actuator.

14. In combination, a power actuator having a rotatable chuck, and a.torque wrench unit adapted for detachable connection with said actuatorcomprising speed reducing gearing and a rotatable wrench member driventhrough said reduction gearing, and being adapted for engagement with anelement to be tightened, a rotatable driver provided with a shankreceivable in said chuck and rotatable thereby, means for yieldablymounting said wrench unit formovementrearwardly longitudinally withrespect to said power actuator, and an extensible driving connectionbetween said driver and said speed reducing gearing whereby thelattermay be driven in all longitudinal positions of said wrench unitwithrespect to said power actuator. H

JOHN C. CURTIS, I

GEORGE B. THOMPSON.

asrsasuos's oi'rso The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 389,402 Moser Sept. 11,18881,823,426 Ferris a Sept. 15, 1931 1,975,984; Stoll Oct. 9, 19341,985,916 Coates et a1. Jan. 1, 1935 2,Q6 9,882 Hall Feb. 9, 1937$165,382 Temple July 18, 1939 2,235,235 Priceg Mar. 18, 1941 OsgoodSept. 22, 1942

